Apparatus for transmitting indications to a distance



July 6, 1937. G. F. SHOTTER 2,086,444

APPARATUS FOR TRANSMITTING INDICATIONS TO A DISTANCE Filed July 26, 19532 Sheets-Sheet l July 6; 1937. G. F. SHOTTER APPARATUS FOR TRANSMITTINGINDICATIONS TO A DISTANCE Filed July 26, 1933 2 Sheets-Sheet 2 HILHHPatented July 6, 1937 untrue Frederick F A U XSTANCE .l'l Barnet,London,

England Application July 26,

1933, Seria No. 682,184

in Great B ain August 5, 1932 9 Claims.

The present invention relates to apparatus for transmitting movements toa distance and has for its object an arrangement whereby the forcesexerted by the transmitting elements on 5 the device which is moving,which may, for instance, be the rotating element of a watt-hour meter,are negligible.

One of the features of the present invention concerns an apparatus forproducing impulses 1g of alternating magnetic flux corresponding innumber to the extent of movement of a movable member to enable suchextent of movement to be transmitted. to a distant point, withoutemploying operating contacts on the movable mem- 15 ber.

Another feature of the invention, broadly stated, relates to anarrangement comprising two magnetic circuits and a conducting; memberhaving its movement controlled by the movable w member. An alternatingiiux preferably of constant magnitude, is applied to one magneticcircult and the movement of the conducting member intermittently causesthe first magnetic circuit to produce flux changes in the secondmagnetic circuit as it moves.

Preferably the changes in magnetic flux cause impulses of alternatingcurrent to be induced in a secondary circuit which on rectificationoperates a relay to send impulses to a distant 3U station.

A further feature of the invention relates to the provision ofindicating devices at the receiving end of the line. These indicatingdevices comprise a series of integrating pointers 3., Which give anindication of the total power consumed in the load circuit at thetransmitting point and two further pointers which alternately serve toindicate the load consumption over the last completed predeterminedperiod of time to lo indicate the load consumption which has taken placesince the beginning of the pending period.

A fourth indicating pointer serves to indicate the extent of the pendingperiod of time which has elapsed at any instant.

These and other features of. the invention not specifically mentionedwill be understood from the following description, taken in conjunctionwith the accompanying drawings, in which:

Fig. 1 shows a front View of one form of apco paratus employed fortransmitting impulses.

Fig. 2 shows a side view of Fig. 1.

Fig. 3 shows an underside view of Fig. 1.

Fig. 4 shows the circuit arrangements employed when using the apparatusshown in Figs.

55 1, 2, and 3.

(C1. it'll- 351) Fig. 5 shows an elevation of an alternative form ofapparatus employed for transmitting impulses, and

Fig. 6 shows a plan view of Fig. 5.

The embodiments shown in the drawings are designed for the purpose oftransmitting impulses over a line to operate a recording instru ment inaccordance with the power consumption in a circuit. The powerconsumption is measured at the transmitting end by means of a wattmeterof. any known type. As shown in Figs. 1 and 2 the wattmeter elementscomprise the well known C-shaped voltage core l and U-shaped series core2. The voltage core l is provided with a winding 3 connected across thesupply line while the series core 2 is provided with two windings 5 andb one on each limb, these windings being in series with the load and thetwo conductors of the supply line. A disc 8 of elec tro-conductingmaterial, preferably aluminium is arranged to rotate in the air gapformed between the pole pieces of the voltage and series cores, the rateof rotation of the disc being damped by a pair of braking magnets 9. Thedisc 8 is mounted on a spindle it held in suitable bearings H. Theoperation of a wattmeter of this type is well known and hence adescription thereof will not be given.

The apparatus for transmitting impulses in accordance with the speed ofrotation of the disc it comprises a core 52 of magnetic materialprovided with a winding E3 to which is applied an alternating voltagepreferably of constant mag nitude. The pole pieces it of the core it areinturned towards each other and a small air gap exists between them. Thealternating voltage is applied to the winding iii through two terminalsiii shown in Fig. 2. A second core l6 of magnetic material is positionedwith its pole pieces below opposite the pole pieces of the core l2 andspaced a short distance therefrom. Two fur- 1 er cores l'i and if ofmagnetic material are also arranged so that the air gap between theirpole pieces is opposite the air gaps formed by the pole pieces of thecore l2 and the core it. Each of the cores l6, H, and I8 is providedwith windings is, El}, and 2! respectively and these windings areconnected in series in the order winding 2i, winding l9, winding 28.

On the same spindle l0 as the rotating disc 3 is mounted a further disc22 made of conducting material preferably copper and arranged to rotatein the air gap formed by the four cores l2, 66, ii, and i8 as shown inFigs. 1 and 2. Two opposite quadrants of this disc are cut out as shownin Fig. 3 so that thin rings 23 of conducting material are left roundthe circumference of the cut-out quadrants.

The operation of the apparatus is as follows: An alternating voltage ofsubstantially constant magnitude is applied to the terminals of thewinding 13. This alternating voltage traversing the winding It givesrise to an alternating flux in the core 12. Assume that the disc is insuch a position as regards the gaps in it that little or no flux in theair gap cuts the conducting portion of the disc then there will be acertain amount of leakage flux passing from the core 12 to the cores Illand I8 and to the core N3. These fluxes will pass round the cores andinduce currents in the windings 20, 2| and I9 respectively. Now thesethree windings are arranged in series and by connecting up the coilswith particular regard to the direction of the coil windings it is soarranged that the current in the winding I9 is of the same magnitude butopposite in direction to the current in. the two windings 2i] and 2|.These currents cancel out so that the resultant current at the terminals24 and 25 is zero. When conducting material is introduced into the airgap the leakage flux to the cores I6, I! and i8 is not altered but inaddition a further magnetic flux will be set up in. the cores l1 and 18.This flux is due to the fact that with conducting material in the airgap, the leakage flux passing from the core l2 to the core [6 will giverise to eddy currents in the conducting material and the field set up bythe eddy currents will cause an additional fiux to be induced in thecores IT and I 8. This induces a current in the windings 2i and 2! whichis additional to and in the same direction as the current due to theleakage flux alone. The balance of current in the three windings I9, 29and 2! is thus upset and current will flow to the line. 7

From the construction of the disc 22 it will be seen that for eachrevolution of the disc and hence for each revolution of the wattrneterdisc 8, two impulses of alternating current are transmitted. Hencevariation in the speed of rotation of the wattmeter disc, which dependson the consumption of power in the load circuit, is signified by thenumber of impulses transmitted during a definite period of time. Ifthese impulses are arranged to operate a step-by-step mechanism anindication will be given as to the power con sumption in the loadcircuit. The apparatus at the receiving station for giving thisindication will be described later.

Referring now to Fig. 4 this shows the circuit arrangements employedwhen using the transmitting apparatus illustrated in Figs. 1, 2 and 3.The alternating voltage for the winding it can be obtained from anyalternating current supply which is represented for convenience by thealternating current generator 26, the busbars 21 and 28 and theconductors 29. It will be appreciated that it is desirable that thealternating voltage applied to the winding l3 should be of substantiallyconstant magnitude. For this purpose, an auto-transformer is locatedbetween the alternating voltage source 26 and the winding l3, andcomprises a rectangular core 39 having a winding 3| wound on the limb32. The output from. the auto-transformer is taken from the points 33,and in one side of the output circuit is arranged a balancing winding 34wound on the limb 35 of the core 36. This balancing coil is inserted forthe purpose of maintaining constant the alternating voltage in theoutput circuit. The limb 35 is made with a smaller crosssectional areathan the limb 32, and is of such dimensions that it is saturated overthe working range of the instrument. Further, the windings 3| and 3d areconnected in such a manner that the electromotive force induced acrossthe terminals of the winding 34 is in opposition to the electromotiveforce across the terminals and exceeds it by the electromotive forcerequired for the output circuit. t will be appreciated that with asufficiently strong magnetizing force on the limb 33 the limb $15 willbecome saturated, so that variations of magnetizing force will have areduced effect on the winding 34. At the same time the electromotiveforce across the terminals 33 will be measured at a uniform rate withthe result that the electrcmotive force across the resistance 38 will besubstantially constant over quite a wide variation of potential of thealternating current source. A resistance 35 is inserted across theoutput circuit of the auto-transformer to provide a substantiallyconstant load.

This lead is then applied to the winding l3 on the core [2. Theoperation of this part of the system which is of course identical withFig. 1 will not be further describe The alternating current impulses inthe output circuit of the three series connected windings I9, 26 and 2iare taken from the terminals 2% and 25 and applied to a full-waverectifier comprising four dry rectifiers 3 39 and connected up in thewell-known bridge foi "at-ion. A smoothing device comprising a condenserll and inductance 2 are connected up in the output circuit and thedirect current impulses serve to operate a relay 43. Relay 43 inoperating closes at contact i -l a circuit over the line. This circuitincludes a current source it at the transmitting station the two lineconductors and 4? and a relay winding 38 at the receiving station. Thefunction of the relay 43 is to epeat the impulses from the outputcircuit of rectifier over the line to the relay winding 38 whichcontrols the receiving equipment.

A description will now be given of the receiving equipment and in thisconnection it should be pointed out that it is the rate at whichimpulses are transmitted over the Fine which gives a measure of thepower consumption in the circuit at the transmitting end. Since the rateof transmission of impulses varies, the length of the impulses will varywhen using the apparatus in question. It is obvious therefore that allthat is required at the receiving station is stepping mechanism which isoperated by each impluse to allow a shaft to make one step. In theconstruction shown in Fig. 4;, the mechanism takes the form of anescapement device and comprises a disc 43 provided with a number of pins5!] arranged around its circumference. A frame 5| pivoted at 52 isprovided with two arms 53 and 54, one of the pins on the disc, forexample, normally resting against the arm 54. Connected to the frame 5|is an arm of magnetic material which acts as a support for the winding48 and to the end of which is attached a soft iron armature 56. Thisarmature 5 is located between the pole pieces of a permanent horseshoemagnet 57. The frame 5| is spring biased to the position shown in thedrawings by the spring 58 fixed at the point 59.

A driving connection is effected to the disc 49 from the synchronousmotor 60. This motor drives a shaft 63 through Bl and a friction clutch62. T .e shaft 63 serves as a bearing for the shaft 84 on which the disc49 is rigidly mounted. One end of the coil spring 85 is attached to theshaft 63, the other end of the spring being attached to a pin 32 on thedisc 49. The object of the spring is to form an energy storing device tomake up for any lag on the part of the motor when the disc is beingrotated step-by-step. The motor Ell also drives a shaft i555 throughgearing 66, till, the shaft driving a further shaft $58 through twobevel gears 69, iii. The mechanism associated with the shaft 68 will bedescribed later.

The shaft 64 is provided with a gear wheel ll meshing with a gear wheel12 mounted on a shaft 13. The wheel 72 drives a gear wheel M, whichthrough the medium of the shaft '35, worm I6 and gear wheel ill controlsthe operation of the integrating indicators Hi, 58a, 19, 19a, and 80a togive an indication of the total power consumption in the circuit.

Loosely mounted on the shaft it is a frame 83 having an extension 84 tothe end of which is attached a roller 85. The roller 85 is operated by acam 86 rigidly mounted on the shaft 68. The frame 83 is pivoted at 81while to the same pivot is attached a second frame 83 provided with twoarms 89 and 90. An extension 8! of the frame 38 is provided with aroller 92 which bears on a second cam 93 also rigidly mounted on theshaft 68. To the end of the shaft 13 is connected a bevel wheel 94 whichengages with one or other of the two crown wheels 95 and 9%.

These crown wheels form part of a load indicating device which comprisesa dial 91 provided with two pointers 93 and Q9. The pointer 98 isattached to a spindle it? which carries the crown wheel 95 while thepointer 99 is attached to the sleeve WI which carries the crown wheel96. One end of the coil spring Hi2 is attached to the crown wheel 95,the other end being attached to a fixed pin W3. A second coil spring N14is similarly attached to the crown wheel 36 and the pin N03.

The shaft 68 also drives a shaft Hi9 through bevel gearing W5 having a2:1 ratio and bevel gearing it having 1:1 ratio. The shaft it!) drives apointer lil'l which rotates over the W8.

A description. will now be given of the operation of the receivingequipment. An impulse incoming to the winding causes the soft ironarmature 56 to be magnetized to a polarity opposite to that of the polepiece of the magnet 57 against which it is normally in contact. Thearmature will therefore be repelled and the frame 58 will pivot about52. The arm 54 will thereupon be moved out of the path of the pin M9 onthe disc it. The motor drive is so arranged that the disc is rotated ina clockwise direction. It will be understood that when the arm 55 isremoved from the path of the pin it?) the disc will commence to rotate.This rotation will cease when the next pin llii meets the arm 53. At thetermination of the impulse the armature 56 will revert to its originalposition and the arm 53 will be moved out of the path of the pin lit) sothat the disc will make another rotary movement.

The rotary movement of the disc =19 is transmitted through the shaft Mto the gear wheel Ill. The gear wheel 'il meshes with the gear wheel l2and further transmits the drive to the shaft l3 and also through anintermediate gear wheel to the gear wheel it causing a movement of oneof a series of integrating pointers l8, lea,

19, 19a, 80 or 80a whereby an indication of the total power consumptionin the load circuit may be given. Further the shaft l3 causes therotation of the bevel wheel 94 and assuming the apparatus to be in theposition shown in the drawings, that is to say, the bevel wheel Q6meshes with the crown wheel 96 the latter will be rotated and thepointer 99 will be moved over the dial 9?. The pointer 9 is made shorterthan the pointer 98 and moves over a different scale since it will beappreciated from the description which follows that the two pointers arerotated in opposite directions and the use of a single scale may lead toconfustion.

The bevel wheel .l l remains in engagement with the crown wheel 95 for apredetermined time which may be, for instance, fifteen seconds. At thetermination of this period the crown wheel 98 is locked against furtherrotation by brake HM- so that the pointer 95; remains in its operatedposition. Further, the shaft i3 is now rocked so that the bevel wheel iliis disengaged from the crown wheel 96 and engages with the crown wheel95 whereupon on the reception of further impulses over the line thepointer 92 is rotated. The pointer 99 remains in its operated positionuntil the end of the next fifteen second period when it is reset tonormal. It will be appreciated therefore that during any particularperiod one of the pointers is intermittently rotated by im- 1 pulsesincoming over the line while the other pointer shows the load upon thecircuit for the previous period.

A description will now be given of the arrangement whereby the drive istransferred from the crown wheel 96 to the crown Wheel It will beremembered that two cams 86 and 93 are rigidly fixed on the shaft 68.Both these cams comprise a raised portion which extends over half thecircumference, and as the cams are rotated by the shaft 68 the rollers85 and 92 will be operated upon by the cam surfaces since they arepressed against the surfaces by springs ill and H2 respectively. Thecams, however, are mounted on the shaft it in such a manner that thecams are displaced angularly with respect to one another. As the shaftis rotated and assuming the rollers to be on the raised portions of thecam surfaces as shown in the drawings, the lower portion of the cam 93is reached. by roller 92 prior to the lower portion of the cam 86 beingreached by the roller 85.

As the roller 92 drops on to the lower surface a frame 88 will pivotabout S'l so that the stud M3 attached to the arm 96 will be moved fromthe surface of the crown wheel 95, whereupon the spring i832 which wastensioned when the crown wheel 95 was operated causes the res-- torationof the pointer 93 to normal, while the stud i M attached to the arm 85is pressed against the surface of the crown wheel 965 so that thepointer 99 is locked in its operated position. The displacement of thecams 36 and is necessary so that the stud li i locks the crown wheel iiibefore the bevel wheel 94 disengages from the teeth thereof.Disengagement of the bevel wheel is caused by the rocking movement ofshaft l3 about the pivot ill, the rocking movement being transmittedthereto by the frame This sequence of operations may be briefly statedas follows: At the end of the operating period for the pointer es theframe 83 is rocked whereupon the stud il l brakes the crown wheel 96while the stud H3 releases the crown wheel $5 which restores to normalwhereupon the frame 33 is rocked and the bevel wheel 94 is disengagedfrom the crown wheel 96 and engages with the crown wheel whereupon thedrive is transmitted to the pointer 98.

The pointer I01 which rotates over the dial I08 is so arranged that itmakes one complete revolution for every half revolution of the shaft 68.This pointer is adjusted so that at the commencement of a period it willbe in the zero position so that it will be appreciated that at anymoment the reading of this pointer gives an indication of the time whichthe particular period has to run before its termination.

It will be appreciated that the shaft 68 is rotated continuously, whilethe shaft I3 which controls the movements of the pointers 98 and 99 isrotated intermittently by the reception of impulses. Hence thechangeover from one indicating pointer 98 to the other indicatingpointer 99 takes place continuously whether any impulses are incoming ornot.

A further method of transmitting impulses is shown in Figs. 5 and 6. Inthese figures a core I30 of magnetic material is provided with a windingI 3I to which is applied at the terminals I32 and I33 an alternatingvoltage, preferably of constant magnitude. The magnetic core I30 hasinturned pole pieces I34 and I35, between which is a small air gap. Astrip I36 of conducting material, for instance, copper, and having acentral slot I31 terminating in two cut-out portions I38 and I39 one ateach end of the strip, is mounted on a spindle I40 on which is alsomounted the rotating element of the watt meter in a similar manner tothat shown in Fig. 1. As one end of the strip passes through the air gapformed by the pole pieces I34 and I35, the other end. passes through anair gap formed by the pole pieces I lI and I42 of a magnetic core I 43provided with a winding I44. The win-ding I44 is brought out to theterminals I45 and I 46 which are connected either directly to terminalsI47 and I48, or, if necessary, in series with a compensating winding I49 located on the magnetic core I30. The spindle I40 is insulated fromthe copper strip I36 by an' insulating bush I50, while iron screens I 5|and I52 may, if necessary, be provided for preventing any interaction ofleakage flux from one core to the other.

The operation of this arrangement is as follows: When the copper stripenters the magnetic field set up by the flux in the core I30, currentswill be caused to flow round the copper strip. These currents, by virtueof the slot in the strip, will take a definite path round the strip, andwill induce an alternating flux into the core I 43. This alternatingflux will give rise to an alternating current in the winding I44.

The purpose of the winding I49 is to compensate for any leakage fluxwhich may pass from the core I30 to the core I43. This leakage flux willinduce a current in the winding I44. Further a current is induced in thewinding I49 due to the alternating flux in the core I30 and the windingI49 is so arranged that the current therein is of the same magnitude butof opposite direction to the current in the coil I44- due to the leakageflux. The two currents therefore cancel out and the resultant current atthe terminals I45 and I46 is zero.

I claim:

1. A device for producing impulses of alternating current correspondingin number to the extent of movement of an integrating meter element,comprising a magnetic circuit, a second magnetic circuit, means forintermittently and inductively linking said first magnetic circuit withsaid second magnetic circuit, an integrating meter element the extent ofmovement of which is to be determined, said integrating meter elementbeing mechanically connected to said linking means to effect themovement of said linking means, and means controlled by said secondmagnetic circuit and responsive, when said first and second magneticcircuits are linked together, to cause the generation of an electriccurrent impulse.

2. A device for producing impulses of alternating current correspondingin number to the extent of movement of an integrating meter element,comprising a magnetic circuit, a source of alternating current, a coilembracing said magnetic circuit and connected to said source, a secondmagnetic circuit, a coil embracing said second magnetic circuit, meansfor intermittently and inductively linking said first magnetic circuitwith said second magnetic circuit, an integrating meter element theextent of movement of which is to be determined, said integrating meterelement being mechanically connected to said linking means to effect themovement thereof, and means controlled by said second magnetic clrcuitand responsive, when said first and second magnetic circuits are linkedtogether to cause the generation of an electric current impulse in saidsecond coil.

3. A device for producing impulses of alternating current correspondingin number to the extent of movement of an integrating meter element,comprising a magnetic circuit, a source of alternating current, a coilembracing said magnetic circuit and connected to said source, a secondmagnetic circuit, a coil embracing said second magnetic circuit, meansfor compensating for the alternating current induced in said second coildue to leakage flux from said first magnetic circuit, means forintermittently and inductively linking said first magnetic circuit withsaid second magnetic circuit, an integrating meter element the extent ofmovement of which is to be determined, said integrating meter elementbeing mechanically connected to said linking means to effect themovement thereof, and means controlled by said second magnetic circuitand responsive, when said first and second magnetic circuits are linkedtogether to cause the generation of an electric current impulse in saidsecond coil.

4. A device for producing impulses of alter nating current correspondingin number to the extent of movement of an integrating meter elementcomprising a magnetic circuit, a source of alternating current, a coilembracing said magnetic circuit and connected to said source, a secondmagnetic circuit, a coil embracing said second magnetic circuit, a thirdmagnetic circuit, a coil embracing said third magnetic circuit andconnected in series with said second coil, the coil windings of saidsecond and third magnetic circuits being disposed with respect to saidfirst magnetic circuit that the current induced by the leakage flux fromsaid first magnetic circuit in said second coil is of the same magnitudebut opposite in direction to the current induced by the leakage fluxfrom said first magnetic circuit in said third coil, means forintermittently and inductively linking said first magnetic circuit withsaid second magnetic circuit, an integrating meter element the extent ofmovement of which is to be determined, said integrating meter elementbeing mechanically connected to said linking means to effect themovement thereof, and means controlled by said second magnetic circuitand responsive, when said first and second magnetic circuits are linkedtogether to cause the generation of an electric current impulse in saidsecond coil which is unaffected by the electric current impulsesgenerated therein by the leakage flux from said first magnetic circuit.

5. A device for producing impulses of alternating current correspondingin number to the extent of movement of an integrating meter elementcomprising a magnetic circuit, a second magnetic circuit, means forexciting said first magnetic circuit with alternating fiux, means forintermittently and inductively linking said first magnetic circuit withsaid second magnetic circuit, an integrating meter element the extent ofmovement of which is to be determined, said integrating meter elementbeing mechanically connected to said linking means to effect themovement thereof, said linking means being adapted to have currentinduced therein by said first magnetic circuit or not according as towhether it inductively links said first and second magnetic circuits ornot on movement of said integrating meter element, the current, wheninduced in said linking means, being adapted to react on said secondmagnetic circuit to cause the generation of an electric current impulse.

6. A device for producing impulses of alternating current correspondingin number to the extent of movement of an integrating meter elementcomprising a magnetic circuit, a second magnetic circuit positioned withrespect to said first magnetic circuit so that it forms an air gaptherewith, means for exciting said first magnetic circuit withalternating fiux, a conductor member disposed in said air gap forintermittently and inductively linking said first magnetic circuit withsaid second magnetic circuit, an integrating meter element mechanicallyconnected to said conductor member to effect the movement thereof, saidconductor member having a discontinuous surface and being adapted tohave current induced in it by said first magnetic circuit or not,according to the position of its surface with respect to said firstmagnetic circuit upon movement of said integrating meter element, thecurrent, when induced in said conductor member, being adapted to reacton said second magnetic circuit to cause the generation of an electriccurrent impulse.

'7. A device for producing alternating current impulses corresponding innumber to the extent of movement of an integrating meter elementcomprising a magnetic circuit, a second magnetic circuit positioned withrespect to said first magnetic circuit so that it forms an air gaptherewith, means for exciting said first magnetic circuit withalternating fiux, a circular disc of conducting material disposed insaid air gap for intermittently and inductively linking said firstmagnetic circuit with said second magnetic circuit, an integrating meterelement the extent of movement of which is to be determined, saidintegrating meter element being mechanically connected to said disc toeffect the movement thereof, said disc of coni ducting material having agap therein and being adapted to have current induced in it by saidfirst magnetic circuit or not according to the position of the gap withrespect to said circuit upon movement of said integrating meter element,the current when induced in said disc being adapted to react on saidsecond magnetic circuit to cause the generation of an electric currentimpulse.

8. A device for producing current impulses corresponding in number tothe extent of movement of an integrating meter element comprising amagnetic circuit having an air-gap, a second magnetic circuit alsohaving an air-gap, means for exciting said first magnetic circuit withalternating fiux, a strip of conducting material for intermittently andinductively linking said first magnetic circuit with said secondmagnetic circuit, an integrating meter element the extent of movement ofwhich is to be determined, said integrating meter element beingmechanically connected to said strip to effect the movement thereof,said strip having a central slot and being adapted to be rotated by saidintegrating meter element and embrace the flux passing through theair-gap of the first magnetic circuit at the same time as it is in theair-gap of the second magnetic circuit, whereby current will be inducedin it by said first magnetic circuit or not according to its positionwith respect to the gaps of said circuits, the current, when induced insaid strip being adapted to react on said second magnetic circuit tocause the generation of an electric current impulse.

9. In combination in a system, for determining the extent of movement ofan integrating meter element, a magnetic circuit, a second magneticcircuit, means for intermittently and inductively linking said firstmagnetic circuit with said second magnetic circuit, an integrating meterelement the extent of movement of which is to be determined, saidintegrating meter element being mechanically connected to said linkingmeans to effect the movement of said linking means, means controlled bysaid second magnetic circuit and responsive, when said first and secondmagnetic circuits are linked together, to cause the generation of anelectric current impulse, and registering means responsive to eachelectric current impulse to give an indication of the number of impulsestransmitted.

GEORGE F. SHOTTER.

